Fuel cells are electrochemical devices that produce usable electricity by the catalyzed combination of a fuel such as hydrogen and an oxidant such as oxygen. In contrast to conventional power plants, such as internal combustion generators, fuel cells do not utilize combustion. As such, fuel cells produce little hazardous effluent. Fuel cells convert hydrogen fuel and oxygen directly into electricity, and can be operated at higher efficiencies compared to internal combustion generators. Because individual fuel cells do not produce much energy (e.g., between about 0.7-0.9 volts), multiple fuel cells may be arranged together in a stack to generate enough electricity to operate motor vehicles and supply electricity to remote locations.
A fuel cell, such as a proton exchange membrane (PEM) fuel cell, typically contains a membrane electrode assembly (MEA) formed by a catalyst coated membrane disposed between a pair of gas diffusion layers. The catalyst coated membrane itself typically includes an electrolyte membrane disposed between a pair of catalyst layers. The respective sides of the electrolyte membrane are referred to as an anode portion and a cathode portion. In a typical PEM fuel cell, hydrogen fuel is introduced into the anode portion, where the hydrogen reacts and separates into protons and electrons. The electrolyte membrane transports the protons to the cathode portion, while allowing a current of electrons to flow through an external circuit to the cathode portion to provide power. Oxygen is introduced into the cathode portion and reacts with the protons and electrons to form water and heat.
MEAs are typically sealed with gaskets to prevent pressurized gases and liquids from escaping. To ensure that the pressurized gases and liquids do not bypass the electrolyte membranes, the gaskets are generally molded around the peripheral edges of the MEAs. However, a common issue with gasket molding systems is that the systems may over-compress or under-compress the MEAs. Over-compression may cause the anode portions and the cathode portions of the MEAs to contact through the respective electrolyte membranes, resulting in electrical shorts. Alternatively, under-compression may result in gasket materials being molded in undesirable locations around the MEAs. Accordingly, there is a need for a gasket molding system that reduces the risk of over-compressing and under-compressing MEAs during gasket molding operations.